Cork flooring

[CCR]

The price is about the same I paid for mine for a good quality cork laminate. From my knowledge base, the plastic is specified only if you're installing on or below grade concrete (with or without a vapor barrier. Since yours is cushion-backed, the additional sheet cushioning is typically not necessary. However, I have seen the addtional cushion layer used with cushion backed planks to provide additional sound-proofing and provide a bit more of a "wood-like" sound with wood style laminates and engineered wood laminates. Of course, you're right on track Feather Finishing the uneven seams. I suspect the flatness of the surface is supposed to be 1/8" in 10.